2,041 research outputs found
Individual growth and foraging responses of age-0 largemouth bass to mixed prey assemblages during winter
We conducted an outdoor pool experiment at a mid-temperate latitude (Ohio, 40°N) to determine how commonly occurring prey assemblages affect individual foraging and growth of individually marked, age-0 largemouth bass during winter. The treatments were low prey, bluegill prey only, macroinvertebrates only, and bluegill plus macroinvertebrates. Across all treatments, growth in mass (g) was unrelated to body size. Conversely, small individuals lost more energy (kJ) than large counterparts in all but the macroinvertebrate-only treatment. With low prey, overall growth of largemouth bass was negative, with losses varying among individuals by 30% and 60% for mass and energy content, respectively. Counterparts in bluegill-only pools also consistently lost mass and energy, with less variability (15% mass; 30% energy). In the macroinvertebrate-only treatment, 31% of individuals gained mass, reflecting the greatest range in mass (100%) and energy (60%) change. With macroinvertebrates plus bluegill, overall growth was generally negative, with intermediate variance among individuals. Variation in growth among individuals typically increased with the frequency that prey occurred in diets during sampling. Apparently, some individuals were inactive, foraged infrequently, and consistently lost intermediate quantities of mass and energy. Others were active and foraged with variable success. Because activity and growth vary among individuals as a function of prey composition during winter, prey assemblages during this season will affect patterns of first-year survival and cohort strength.Funding for this project was provided by National Science Foundation grant DEB 9407859 to R.A.S. and Federal Aid in Sport Fish Restoration Project F-69-P, administered jointly by the U.S. Fish and Wildlife Service and Ohio Division of Wildlife
Identification of single nucleotide polymorphisms in the bovine Toll-like receptor 1 gene and association with health traits in cattle
Bovine mastitis remains the most common and costly disease of dairy cattle worldwide. A complementary control measure to herd hygiene and vaccine development would be to selectively breed cattle with greater resistance to mammary infection. Toll-like receptor 1 (TLR1) has an integral role for the initiation and regulation of the immune response to microbial pathogens, and has been linked to numerous inflammatory diseases. The objective of this study was to investigate whether single nucleotide polymorphisms (SNPs) within the bovine TLR1 gene (boTLR1) are associated with clinical mastitis (CM)
Electro-kinetic technology as a low-cost method for dewatering food by-product
Increasing volumes of food waste, intense environmental awareness, and stringent legislation have imposed increased demands upon conventional food waste management. Food byproducts that were once considered to be without value are now being utilized as reusable materials, fuels, and energy in order to reduce waste. One major barrier to the valorization of food by-products is their high moisture content. This has brought about the necessity of dewatering food waste for any potential re-use for certain disposal options. A laboratory system for experimentally characterizing electro-kinetic dewatering of food by-products was evaluated. The bench scale system, which is an augmented filter press, was used to investigate the dewatering at constant voltage. Five food by-products (brewer’s spent grain, cauliflower trimmings, mango peel, orange peel, and melon peel) were studied. The results indicated that electro-kinetic dewatering combined with mechanical dewatering can reduce the percentage of moisture from 78% to 71% for brewer’s spent grain, from 77% to 68% for orange peel, from 80% to 73% for mango peel, from 91% to 74% for melon peel, and from 92% to 80% for cauliflower trimmings. The total moisture reduction showed a correlation with electrical conductivity (R2¼0.89). The energy consumption of every sample was evaluated and was found to be up to 60 times more economical compared to thermal processing
The Micro-Randomized Trial for Developing Digital Interventions: Data Analysis Methods
Although there is much excitement surrounding the use of mobile and wearable
technology for the purposes of delivering interventions as people go through
their day-to-day lives, data analysis methods for constructing and optimizing
digital interventions lag behind. Here, we elucidate data analysis methods for
primary and secondary analyses of micro-randomized trials (MRTs), an
experimental design to optimize digital just-in-time adaptive interventions. We
provide a definition of causal "excursion" effects suitable for use in digital
intervention development. We introduce the weighted and centered least-squares
(WCLS) estimator which provides consistent causal excursion effect estimators
for digital interventions from MRT data. We describe how the WCLS estimator
along with associated test statistics can be obtained using standard
statistical software such as SAS or R. Throughout we use HeartSteps, an MRT
designed to increase physical activity among sedentary individuals, to
illustrate potential primary and secondary analyses
“Hearing from All Sides” How Legislative Testimony Influences State Level Policy-Makers in the United States
Background:
This paper investigates whether state legislators find testimony influential, to what extent
testimony influences policy-makers’ decisions, and defines the features of testimony important in affecting
policy-makers’ decisions.
Methods:
We used a mixed method approach to analyze responses from 862 state-level legislators in the
United States (U.S.). Data were collected via a phone survey from January-October, 2012. Qualitative data
were analyzed using a general inductive approach and codes were designed to capture the most prevalent
themes. Descriptive statistics and cross tabulations were also completed on thematic and demographic
data to identify additional themes.
Results:
Most legislators, regardless of political party and other common demographics, find testimony
influential, albeit with various definitions of influence. While legislators reported that testimony
influenced their awareness or encouraged them to take action like conducting additional research, only
6% reported that testimony changes their vote. Among those legislators who found testimony influential,
characteristics of the presenter (e.g., credibility, knowledge of the subject) were the most important aspects
of testimony. Legislators also noted several characteristics of testimony content as important, including use
of credible, unbiased information and data.
Conclusion:
Findings from this study can be used by health advocates, researchers, and individuals to
fine tune the delivery of materials and messages to influence policy-makers during legislative testimony.
Increasing the likelihood that information from scholars will be used by policy-makers may lead to the
adoption of more health policies that are informed by scientific and practice-based evidence
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Magnesium intake, plasma C-peptide, and colorectal cancer incidence in US women: a 28-year follow-up study
Background: Laboratory studies suggest a possible role of magnesium intake in colorectal carcinogenesis but epidemiological evidence is inconclusive. Method: We tested magnesium–colorectal cancer hypothesis in the Nurses' Health Study, in which 85 924 women free of cancer in 1980 were followed until June 2008. Cox proportional hazards regression models were used to estimate multivariable relative risks (MV RRs, 95% confidence intervals). Results: In the age-adjusted model, magnesium intake was significantly inversely associated with colorectal cancer risk; the RRs from lowest to highest decile of total magnesium intake were 1.0 (ref), 0.93, 0.81, 0.72, 0.74, 0.77, 0.72, 0.75, 0.80, and 0.67 (Ptrend<0.001). However, in the MV model adjusted for known dietary and non-dietary risk factors for colorectal cancer, the association was significantly attenuated; the MV RRs were 1.0 (ref), 0.96, 0.85, 0.78, 0.82, 0.86, 0.84, 0.91, 1.02, and 0.93 (Ptrend=0.77). Similarly, magnesium intakes were significantly inversely associated with concentrations of plasma C-peptide in age-adjusted model (Ptrend=0.002) but not in multivariate-adjusted model (Ptrend=0.61). Results did not differ by subsite or modified by calcium intakes or body mass index. Conclusion: These prospective results do not support an independent association of magnesium intake with either colorectal cancer risk or plasma C-peptide levels in women
Differences in Relative Abundance of GnRH-I and GnRH-II in Granulosa Cells of Bovine Antral Follicles at Specific Stages of Follicular Development
Increased estradiol is the primary signal to initiate standing estrus, and cows that exhibit estrus prior to fixed-time artificial insemination have greater pregnancy rates than cows that do not. Therefore, understanding what factors may be present at the ovary that may regulate estradiol production is critical. A previous study reported that bovine follicles with greater follicular fluid concentrations of estradiol had decreased expression of GnRH-I and GnRH-II in granulosa cells (GC). The objective of this study was to characterize relative abundance of GnRH-I and -II mRNA within GC of follicles at specific stages of development. Beef cows were synchronized, and ovaries were collected at specific stages of follicular development [pre-selection (PRE), post-selection (POST), and post-selection 24 h after luteal regression (POST-PG)]. All surface follicles were classified as small (\u3c 5mm), medium (5 - 8mm), or large (\u3e 8mm) and aspirated to collect GC. Large follicles from each animal were kept separate and all other follicles were pooled by size within animal (n = 27, 27, and 18 for small, medium, and large). Total cellular RNA was extracted, and RT-PCR was performed for GnRH-I, GnRH-II, and GAPDH. Data were analyzed using the MIXED procedure of SAS. Across all follicles, GnRH-I and GnRH-II expression were not influenced by stage (P = 0.27) but were influenced by size (P \u3c 0.01). Smalls (4.55 ± 0.39 and 3.91 ± 0.44, respectively) had greater expression (P ≤ 0.01) of GnRH compared to mediums (0.83 ± 0.39 and 1.41 ± 0.44, respectively) and larges (0.52 ± 0.47 and 2.12 ± 0.54, respectively). There was also a stage by size interaction (P \u3c 0.01). POST (P \u3c 0.01) and POST-PG (P ≤ 0.08) smalls had or tended to have increased expression compared to PRE smalls, but PRE mediums had increased expression (P \u3c 0.03) compared to POST-PG mediums. When only the largest follicle for each animal was evaluated, stage of development influenced expression of GnRH-I (P = 0.03) but not GnRH-II (P = 0.91). For GnRH-I, PRE tended (P = 0.09; 2.29 ± 0.55) to have increased expression compared to POST (0.92 ± 0.55) and did have greater expression compared to POST-PG (P = 0.01; 0.11 ± 0.55). Thus, GnRH within antral follicles may be a key regulator of the follicle’s ability to produce estradiol
Good practice in food-related neuroimaging
The use of neuroimaging tools, especially functional magnetic resonance imaging, in nutritional research has increased substantially over the past 2 decades. Neuroimaging is a research tool with great potential impact on the field of nutrition, but to achieve that potential, appropriate use of techniques and interpretation of neuroimaging results is necessary. In this article, we present guidelines for good methodological practice in functional magnetic resonance imaging studies and flag specific limitations in the hope of helping researchers to make the most of neuroimaging tools and avoid potential pitfalls. We highlight specific considerations for food-related studies, such as how to adjust statistically for common confounders, like, for example, hunger state, menstrual phase, and BMI, as well as how to optimally match different types of food stimuli. Finally, we summarize current research needs and future directions, such as the use of prospective designs and more realistic paradigms for studying eating behavior
Influence of Bovine Viral Diarrhea Virus Infection on Artificial Insemination Conception and Breeding Season Pregnancy Success in Vaccinated Beef Herds
Bovine Viral Diarrhea Virus (BVDV) causes reproductive economic losses in cattle. The objective of this study was to evaluate the influence of BVDV infection on reproductive success. Vaccinated cows (n = 370) and heifers (n = 528) from nine different herds were synchronized using the 7-day CO-Synch + CIDR protocol and were bred using fixed-time artificial insemination (FTAI). On d 28 following insemination, blood samples were collected and pregnancy status was determined. Non-pregnant animals were resynchronized and FTAI occurred a second time. In six herds, bulls were comingled with females beginning 10-15 d after the second AI. Final pregnancy status was determined 33-80 d following the first pregnancy diagnosis. Blood samples were tested for the presence of BVDV antigen using the IDEXX BVDV PI X2 Kit. Animals that tested positive were considered infected with BVDV at the time of blood collection. Herds were determined to be BVDV infected by the presence of at least one animal having a positive test for antigen (n = 4 infected herds, n = 5 non-infected herds). Statistical analyses were performed using the GLIMMIX procedure of SAS with herd as a random variable. Herds that had evidence of BVDV infection at d 28 following insemination had significantly decreased (P \u3c 0.01) first service AI conception rates compared to herds that had no evidence of infection (34 ± 2.3% vs. 54 ± 2.3%, respectively). Additionally, breeding season pregnancy rates were decreased (P \u3c 0.01) in BVDV infected herds compared to non-infected herds (69 ± 3.4% vs. 80 ± 3.6%, respectively). There was no significant effect of BVDV infection status on embryonic loss (P = 0.42) or percentage of animals which lost a pregnancy and rebred by the end of the breeding season (P = 0.63). In conclusion, BVDV infection in well vaccinated herds had a significant negative impact on both first service AI conception rate and overall breeding season pregnancy success
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